The present patent application relates to a rotor blade for a wind turbine. Further, it relates to a kit of parts for adapting a wind turbine to a site constraint. Finally, the present patent application relates to a method for adapting a rotor of a wind turbine to site constraints.
Wind energy systems have gained more and more importance as a source of energy in recent years. Thus, manufacturers of wind turbines are building more powerful wind turbines that are growing in size such that rotor blades of wind turbines could easily reach the length of 60 m. Wind turbines are classified in different type classes or wind classes that are used for technical certification. The wind or type classes are sorted by different extreme wind velocities and the long term annual mean wind speeds. Four different type classes exist. Therefore, wind turbines are designed for one specific wind or type class out of the four available classes. Accordingly, the manufacturers provide only a limited set of blades for each type class of a wind turbine, wherein the blades are adapted to the different average wind speeds or other situations of the specific wind class. Generally the sites, where a wind turbine is erected, do not exactly comply with a typical wind situation of the wind class of the site. Thus, the turbines are hardly ever used at the conditions they are designed for.
Further to the above, the operators of a wind park often choose a specific wind class or type class in which the turbine should survive 20 years of service. As the wind classes cover a large range of wind speeds, a wind turbine for a specific wind class should able to be operated even at the highest possible wind speeds, i.e. the upper end of the range, in that class. But for the majority of the sites, the wind speeds do not reach the upper end of the range of a specific wind class. Therefore, a wind turbine provided for that wind class does not utilize its complete capability. Even within a wind park, there may be different constraints for individual wind turbines. For example, some wind turbines may be allowed to produce more noise than others due to administrative regulations, some wind turbines may be on mountain ridges, some may be placed less favorable and therefore run at milder loads than designed for.